Analysis on Damage Factors of Jilake Reservoir TII, Tarim Basin and the Countermeasures
Huifeng Liu,
Zhixiong Xu,
Wanjun Li,
Qi Liu,
Dongdong Hou,
Ping Yang,
Chuanyi Zhou
Issue:
Volume 9, Issue 3, September 2021
Pages:
30-35
Received:
26 June 2021
Accepted:
10 July 2021
Published:
29 July 2021
Abstract: Jilake Reservoir TII in Tarim Basin, China, is characterized in high clay content, great water sensitivity, small difference between formation pressure and dew point pressure, severe retrograde condensation pollution, water output of gas reservoir and serious water blocking at the low-permeability position of the reservoir, imposing restrictions on the productivity of oil & gas wells. Sensitivity experiments showed that Jilake Reservoir TII was strongly sensitive to water, weakly sensitive to alkali and weakly sensitive to stress. Dynamic core displacement results showed that conventional water-based drilling fluid causes 40% permeability damage. SEM imaging indicated illite/smectite on the rock surface swelled and blocked the primary pore after encountering the drilling fluid. Besides, conventional water-based fracturing fluid caused 70%-90% damage to the permeability, and the SEM results also showed clay minerals swelling after absorbing water from the fracturing fluid. Experiments also showed that that the damage of retrograde condensation was also serious and 15% condensate oil reduced the gas permeability by 30%-60%. Moreover, water blocking damage also occurred to Jilake Reservoir TII, and the damage extent of gas permeability was a function of water saturation. However, the damage can be remitted by adding clay stabilizer and reverse wetting agent into the operating fluid. The laboratory tests indicated that the anti-swelling rate of the clay stabilizer reached 143.8%; the addition of the reverse wetting agent resulted in permeability increase by 3 times for formation water and 1.76 times for condensate oil.
Abstract: Jilake Reservoir TII in Tarim Basin, China, is characterized in high clay content, great water sensitivity, small difference between formation pressure and dew point pressure, severe retrograde condensation pollution, water output of gas reservoir and serious water blocking at the low-permeability position of the reservoir, imposing restrictions on...
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First Community in Abandoned Pasture Lands or Crops in Eastern Cuba’s Rainforest over Metamorfics Rocks
Orlando Joel Reyes,
Félix Acosta Cantillo,
Luz Margarita Figueredo Cardona,
Pedro Bergues Garrido
Issue:
Volume 9, Issue 3, September 2021
Pages:
36-41
Received:
5 July 2021
Accepted:
10 August 2021
Published:
19 October 2021
Abstract: Miconio prasinae–Cyatheion arboreae alliance is described. Although it has five associations, we address three in this work, corresponding to immediate, secondary and early successional communities in abandoned pasture lands or crops in submountains rainforest over metamorphic rocks. The objective of this work is to study the first communities in used and abandoned fields, because they are of a great importance in the understanding of the vegetation’s evolution and for management purposes. In the submontane forest on the metamorphic complex, the destruction of mature vegetation produces important losses in climatic biodiversity and transcendental changes in ecosystem composition. The change in soil use, especially the transformation to pastureland, has favored the development of herbaceous and shrubby plant communities. This study is not only of practical relevance in describing the associations of the pine forests the plant associations and the study of the ecological conditions in which they develop, but its results can be used as a working tool in the environmental management and silviculture for the restoration of degraded areas. The study of diverse Cuban vegetation types suggests that the methodology of Zurich Montpellier’s school is more effective as compared to other authors because its syntaxa is good to recognize and is able to transform in a forest typology. The main species are pioneers heliophilous with a type of "r" selection.
Abstract: Miconio prasinae–Cyatheion arboreae alliance is described. Although it has five associations, we address three in this work, corresponding to immediate, secondary and early successional communities in abandoned pasture lands or crops in submountains rainforest over metamorphic rocks. The objective of this work is to study the first communities in u...
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